NEUROLOGY & FEMALE UROLOGY

doi: 10.1590/S1677-553820100003000027

Cost analysis of interventions for antimuscarinic refractory patients with overactive bladder
Watanabe JH, Campbell JD, Ravelo A, Chancellor MB, Kowalski J, Sullivan SD
Pharmaceutical Outcomes Research and Policy Program, University of Washington, Seattle, Washington
Urology. 2010 Apr 28. [Epub ahead of print]

• Objectives: To estimate average, initial, and cumulative procedure related costs from a US payer perspective extending up to 3 years for the overactive bladder (OAB) interventions: sacral neuromodulation (SNM), intra-detrusor botulinum toxin A (BoNTA), and augmentation cystoplasty (AC) for antimuscarinic refractory patients.
  Methods: Costs (2007 US dollars) were calculated using Current Procedural Terminology (CPT) codes, Ambulatory Payment Classification (APC) codes; Diagnosis Related Group (DRG) payments, and Healthcare Common Procedure Coding System (HCPCS) Level II Codes extracted from the literature and from the SNM device manufacturer. CPT codes were converted to costs using the Center for Medicare and Medicaid Services (CMS) Relative Value Unit (RVU) fee schedule. Sensitivity analyses were performed to evaluate assumptions and uncertainty of results based on plausible variation in estimates of key cost drivers.
  Results: The initial treatment cost was $22,226, $1,313, and $10,252 for SNM, intra-detrusor injection of BoNTA, and AC respectively. The first-year cost was $23,614, $2626, and $11,637 respectively. Three years after initiating treatment, the cumulative cost was $26,269, $7651, and $14,337 respectively. Sensitivity analyses revealed that SNM persisted as the most costly intervention in all scenarios. The 3-year cumulative cost range produced by the sensitivity analyses for SNM, BoNTA, and AC was $25,384-$27,357, $4586-$11,476, and $12,315-$16,830, respectively.
  Conclusions: All estimates of cost endpoints for SNM were greater than those for BoNTA and AC. These cost estimates, when combined with data on outcomes and risks, are important components of a robust health care technology assessment of antimuscarinic treatment failure options.

• Editorial Comment
  This article examines the cost of treating one of the most difficult populations with voiding dysfunction, those patients who have failed standard antimuscarinic medical therapy. The authors reviewed three of the most common treatments for this population: sacral neuromodulation, augmentation enterocystoplasty, and intra-detrusor botulinum toxin injections. The cost for the three year therapy was projected and compared among the three therapies.
  One of the main challenges of the paper was the cost analysis for projecting the potential cost of botulinum toxin injections in view of its’ non-FDA approved status. Regardless, the article makes an illuminating comment regarding the cost of sacral neuromodulation in comparison with the two other therapies. The summary cost of augmentation enterocystoplasty may be somewhat conservative in its estimation in view that the cost of lifelong self-catheterization may not be clearly accounted. Many surgeons who perform this operation understand that a significant segment of those patients treated will need to practice lifelong self intermittent catheterization secondary to their reconstruction. This is currently no small social cost in the United States in view that the self-catheterization is now supported by the government paying for one-time use disposable catheters. The manuscript has a very illustrative graph with projected costs over a time span. It will be interesting to note at what point the projected cost of botulinum toxin-A injections surpasses augmentation enterocystoplasty in overall cost in view of the steeper slope of the botulinum toxin injection line. In addition, the cost of botulinum toxin injections may vary in time with the potential addition of new manufacturers. Regardless, the utility and decreased comparative expense of botulinum toxin injections for this population should surely impress and excite the reader.

Dr. Steven P. Petrou
Professor of Urology, Associate Dean
Mayo School of Graduate Medical Education
Jacksonville, Florida, USA
E-mail: petrou.steven@mayo.edu